Bought new Moentrol refurb kit

Actually I bought two of them, so I hope they don't suck.
Seems like a good idea though to make things look new, despite
keeping the old water valve in place.

Questions I have are in regard to replacing the shower head and bath spout.
I've done new ones before successfully, but not replacements and I'm wondering if
there are some tricks to that.
Two problems I see:
1) how do you get either the shower head or bath spout to be snug and also directed
downward and aligned properly? I do recall screwing those on and coming to
a point where I thought it looked good, but it was sort of loose and I thought maybe
could go around again. Seems to me I ended up either removing or adding some nylon
tape to make it more snug or more loose. Is that all I can do? Is this one of those things
that you just get good at over time judging, or do even pros have to do this on and off
bit til they get it the right tightness and alignment? Or is there hopefully a magical one
shot neat trick?
2) When I remove the old fixtures, should I go ahead and remove the nipple because I
may have loosened it anyway? Last thing I want is a leak. I'd prefer not to mess with the
connection that's through the wall, but I don't know any way to ensure that it did not unscrew
some while unscrewing the fixture from the opposite end. If it did unscrew a little, is it a bad
idea to just re-tape the outside connection with the new fixture and hope for the best? Or is the
"seal" essentially broken if it unscrews a little and I have to redo both?
Someone had told me once to use both pipe joint compound as well as teflon tape.
That seems to have worked for me in the past. Sound ok to do that way? I aso never really
knew what a good starting amount of tape is. One circumference, two, three?
If I remove the nippel, I had planned on using a 1/2 wire brush to clean out the
female connection inside the wall. Anything else I need to do to prepare it for re-
connection?

I had not thought about the possibility that a different length of pipe nipple might be required.
That certainly adds a wrinkle to the job. Thanks for the leverage tip. Well, I'll take it slow and careful.
Thanks a bunch for your help.

I'll see if I can ascertain whether it has moved at all when I remove the fixture.
If I think it hasn't then I'll leave it, as you suggest.
Thanks for the reply. I'll let you all know how it goes. The parts are due to arrive tonight, so
I thought I'd start removing the fixtures from one of the baths anyway.

One down, one to go. It was a fiasco though. The parts they told me I could use for
my old valve needed a lot of jury rigging to get it to actually work. The adapter could not be screwed
all the way in, or otherwise it ends up leaning forward. The adapter is to accommodate different screwhole
placemet of today's Moen faceplates. So, I ended up screwing it in as much as I could before it started to
lean over. The faceplate screws then end up pulling that adapter piece taught so that it didn't really
matter if the adapter itself was tight.
The lefthand faceplate screw also would not go all the way in. I had to use a metal grinder to grind
off part of the screw stub off the original valve. Now that it's done, it looks great and works well.
But, what a pain.
For anyone interested, this was Moen adapter #145058 that is supposed to work with all their old valves
and any of their "moentrol" kits. If you follow my instructions, you can get it done in a snap, but this first
time around was no fun.